#include <cstdio>

int main( )
{
    int n, i, t1, t2;
    char b[ 20 ];
    while ( scanf("%d", &n) && n )
    {
        scanf("%s", b);
        t1 = t2 = 0;
        for ( i = 0; i < n; i++ )
        {
            if ( b[ i ] == 'R' )
                t1++;
            if ( b[ i ] == 'Y' )
                t2++;
            if ( b[ i ] == 'B' || b[ i ] == 'L' )
                break;
        }
        if ( b[ i ] == 'L' )
            if ( t2 == 7 )
                puts("Yellow");
            else
                puts("Red");
        else
            if ( t1 == 7 )
                puts("Red");
            else
                puts("Yellow");    
    }
    return 0;
}
